The three projects in this PO1 will continue to share a core set of facilities which has two favorable results.[unreadable] First, this sharing is highly effective in cost and management time. Second, students and fellows interact[unreadable] during use of this common equipment promoting collaboration and cross fertilization. All Project Leaders[unreadable] and PI in this Program have offices and laboratories within 100 feet of one another. Some of the facilities[unreadable] supported in part by the PO1 core include a shared darkroom, centrifuges and microscopes. In these[unreadable] cases, maintenance contracts and supplies are supported.[unreadable] A Core facility for shRNA-vector libraries technician for use of short RNA hairpin vectors will be shared by all[unreadable] three projects. This technician will have laboratory space on the same floor as the three projects. All of the[unreadable] projects propose experiments where either large or small libraries of retro viral shRNA vectors will be used.[unreadable] These libraries are currently available from three sources, the Broad Institute RNA/Consortium, a library[unreadable] developed at Cold Spring Harbor by Dr. Greg Hannon, and a library developed by Dr. Ren6 Bernards of the[unreadable] Netherlands Cancer Institute. The RNAi Consortium based at MIT's Broad Institute is led by Professor[unreadable] William Hahn, a consultant to the Core. The Consortium has developed approximately 150,000 shRNA-lentivirus[unreadable] vectors which are targeted to silence approximately 30,000 genes orisoforms of genes. There will[unreadable] be other such libraries developed in the future. The Core will acquire, maintain and develop methods for[unreadable] optimalscreens with these RNAi libraries. The technician will also interact with the Virus Production Core[unreadable] Facility in the Center for Cancer Research. This will be both cost effective and insure a high quality of[unreadable] experimentation. Many of the above viral stocks are arrayed in microtiter dishes and to fully implement their[unreadable] use, a robotic system must be used to automate their distribution.